Osteoarthritis, also known as "wear and tear" arthritis, is a progressive disease
of the joints.

Cause

With osteoarthritis, the articular cartilage that covers the ends of bones in the
joints gradually wears away. Where there was once smooth articular cartilage that
made the bones move easily against each other when the joint bent and straightened,
there is now a frayed, rough surface. Joint motion along this exposed surface is painful.

Osteoarthritis usually develops after many years of use. It affects people who are
middle-aged or older. Other risk factors for osteoarthritis include obesity, previous
injury to the affected joint, and family history of osteoarthritis.

A joint is where the ends of two or more bones meet. The knee joint, for example,
is formed between the bones of the lower leg (the tibia and the fibula) and the thighbone
(the femur). The hip joint is where the top of the thighbone (femoral head) meets
a concave portion of the pelvis (the acetabulum).

A healthy joint glides easily without pain because a smooth, elastic tissue called
articular cartilage covers the ends of the bones that make up the joint.

Osteoarthritis can affect any joint in the body, with symptoms ranging from mild to
disabling.

A joint affected by osteoarthritis may be painful and inflamed. Without cartilage,
bones rub directly against each other when the joint moves. This is what causes the
pain and inflammation. Pain or a dull ache usually develops gradually over time. Pain
may be worse in the morning and feel better with activity. Vigorous activity may cause
pain to flare up.

Hands of a patient with osteoarthritis. Bone growths on the little finger are typical
of osteoarthritis.

The joint may stiffen and look swollen, enlarged or "out of joint." A bump may develop
over the joint.

If bending the joint becomes difficult, motion may be limited.

Loose fragments of cartilage and other tissue can interfere with the smooth motion
of joints. The joint may lock or "stick" when used. It may creak, click, snap, or
make a grinding noise (crepitus). The joint may become weak and buckle.

Although osteoarthritis cannot be cured, early identification and treatment can slow
progression of the disease, relieve pain and restore function.

The doctor will want to know if the joint has ever been injured. He or she will want
to know when the joint pain began and what the pain feels like: Is the pain continuous,
or does it come and go? Does it occur in other parts of the body? It is important
to know when the pain occurs: Is it worse at night? Does it occur with walking, running
or at rest?

The doctor will examine the affected joint in various positions to see if there is
pain or restricted motion. He or she will look for creaking or grinding noises (crepitus)
that indicate bone-on-bone friction. muscle loss (atrophy), and signs that other joints
are involved. The doctor will look for signs of injury to muscles, tendons, and ligaments.

X-rays can show the extent of joint deterioration, including narrowing of joint space,
thinning or erosion of bone, excess fluid in the joint, and bone spurs or other abnormalities.
They can help the doctor distinguish various forms of arthritis.

Sometimes laboratory tests can help rule out other diseases that cause symptoms similar
to osteoarthritis.

Nonsurgical Treatment

Lifestyle ModificationsThe doctor may recommend rest or a change in activities to avoid provoking osteoarthritis
pain. This may include modifications in work or sports activities. It may mean switching
from high-impact activities (such as aerobics, running, jumping, or competitive sports)
to low-impact exercises (such as stretching, walking, swimming, or cycling). A weight
loss program may be recommended, if needed, particularly if osteoarthritis affects
weight-bearing joints (such as the knee, hip, spine, or ankle)

MedicationsNon-steroidal anti-inflammatory drugs can help reduce inflammation. Sometimes, the
doctor may recommend strong anti-inflammatory agents called corticosteroids, which
are injected directly into the joint. Corticosteroids provide temporary relief of
pain and swelling.

Dietary supplements called glucosamine and chondroitin sulfate may help relieve pain
from osteoarthritis. (Caution: The U.S. Food and Drug Administration does not test
or analyze dietary supplements. Always consult your doctor before taking dietary supplements.
)

Physical TherapyA balanced fitness program, physical therapy, and/or occupational therapy may improve
joint flexibility, increase range of motion, reduce pain, and strengthen muscle, bone,
and cartilage tissues. Supportive or assistive devices (such as a brace, splint, elastic
bandage, cane, crutches, or walker) may be needed. Ice or heat may need to be applied
to the affected joint for short periods, several times a day.

Surgical Treatment

If early treatments do not stop the pain or if they lose their effectiveness, surgery
may be considered. The decision to treat surgically depends upon the age and activity
level of the patient, the condition of the affected joint, and the extent to which
osteoarthritis has progressed.

ArthroscopyA surgeon uses a pencil-sized, flexible, fiberoptic instrument (arthroscope) to make
two or three small incisions to remove bone spurs, cysts, damaged lining, or loose
fragments in the joint.

OsteotomyThe long bones of the arm or leg are realigned to take pressure off of the joint.

Joint fusionA surgeon eliminates the joint by fastening together the ends of bone (fusion). Pins,
plates, screws, or rods may hold bones in place while they heal. This procedure eliminates
the joint's flexibility.

Joint replacementA surgeon removes parts of the bones and creates an artificial joint with metal or
plastic components (total joint replacement or arthroplasty).

AAOS does not endorse any treatments, procedures, products, or physicians referenced
herein. This information is provided as an educational service and is not intended
to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance
should consult his or her orthopaedic surgeon, or locate one in your area through
the AAOS "Find an Orthopaedist" program on this website.